Traditional motor and generator structures are usually designed to accommodate rotor assemblies having relatively large spinning diameters located near the axial center of the rotor. Further, the techniques for manufacturing conventional motors typically require assembly of their components in an axial manner. FIGS. 1 and 2 depict the axial assembly of components for typical motor structures.
FIG. 1 illustrates commonly-used motor components and assembly techniques for a traditional brushed direct current (“DC”) electric motor. Brushed DC electric motor 100 includes an end plate 102, a rotor assembly 104, and a housing 106. End plate 102 includes brushes 101 to make and break contact with commutation segments on commutator 103, thereby commutating power to a rotor assembly 104. The rotor assembly also includes a shaft 105 and windings 107. Housing 106 is deep-drawn (i.e., it has been formed to have a deep housing cavity) and is configured to capture a first bearing (not shown) and one end of the shaft 105. Note that housing 106 can provide datum surfaces to locate and align end plate 102. End plate 102 is configured to capture a second bearing (not shown) and the other end of shaft 105. To assemble brushed DC electric motor 100, rotor assembly 104 is axially inserted into housing 106, with end plate 102 subsequently being secured to housing 106.
FIG. 2 illustrates commonly-used motor components and assembly techniques for a traditional brushless direct current (“DC”) electric motor. Brushless DC electric motor 200 includes a first plate 208, a yoke 206 composed of laminations, a rotor assembly 204, and a second plate 202. Laminated yoke 206 supports coils (not shown) and provides a mounting surface for joining first plate 208 with second plate 202. To assemble brushless DC electric motor 200, rotor assembly 204 is inserted axially through the center of laminated yoke 206. Then, first plate 208 is positioned and secured with second plate 202.
While functional, the assembly techniques used to produce motors 100 and 200 are generally suboptimal for motors that have rotors with relatively small spinning diameters near their axial centers and relatively large spinning diameters near their ends.
In view of the foregoing, it would be desirable to provide improved assembly techniques for motors that have rotors with relatively small spinning diameters near their axial centers and relatively large spinning diameters near their ends.